MORPHOLOGICAL DIAGNOSIS OF PANCREATIC NEUROENDOCRINE TUMORS (REVIEW AND CASE REPORT).

Pancreatic neuroendocrine tumors (NETs) are an urgent problem. The issues of diagnosis and treatment of neuroendocrine tumors (NETs) are currently one of the most complex and relevant ones in modern oncological endocrinology. The growing interest in NETs is due to the fact that the incidence rate of this pathology has increased significantly in the world over the past 30-35 years. In the diagnosis of NETs, morphological research is crucial; later it plays an important role in the choice of therapeutic tactics. The morphological diagnosis of a pancreatic NET is based on the classification of the World Health Organization and criteria for assessing NET prognosis. The main study in a pancreatic NET morphological diagnosis is immunohistological (IHC) examination using markers that allow establishing the neuroendocrine nature of the tumor, and markers that determine the potential of tumor malignancy. To determine a NET, it is advisable to use a combination of immune markers such as chromogranin A, synaptophysin, and CD56, and to determine the potential of tumor malignancy, Ki-67, p53, and AMACR. The paper presents a clinical case of morphological diagnosis of a pancreatic NET (VIPoma) from the practical experience of TARGET Cancer Clinic. These recommendations are based on data from the clinical recommendations of the European Neuroendocrine Tumor Society (ENETS), the American National standards for the diagnosis and treatment of malignant tumors (NCCN), a review of the literature for 2014-2019 using search resource PubMed, Pathology Outlines, and CAP (College of American pathologists), and data from patients with pancreatic NETs treated at the TARGET Cancer Clinic.